Sanding machine



May 18, 1954 s. PHlLlBoslAN ETAL. 2,678,522

SNDING MACHINE Filed April 19. 195o w K yglfm ola/Vee f?. @an/f, WILL/AM1 JTOLP AND src-Puffy plm. aan.: MN

ATTORNEYS ll Sheets-Sheet l May 18, 1954 s. lxanJosLkhlv ETAL SANDINGMACHINE `11 sheets-sheet 2 Filed April 19, 1950 STEPHEN Pil/L 0805/4 N`ATTOR N EYJ S. PHILIBOSIAN ETAL.

May 18, 1954 SANDING MACHINE Filed April 19, 195i l1 Sheets-Sheet 5 May18, 1954 s.PH|| lBos1AN ETA. 2,678,522

SANDING MACHINE 11 sneetssheet 4 Filed April 19, 1950 INVENTORS aura?l?. Rome, wu/AM J. .srof ma May 18, 1954 s. PHlLlBoslAN :a1-AL 2,678,522

SANDING MACHINE 11 Sheets-Sheet 5 Filed April 19. 195o IN VEN TORSUlli/6 6. RUWE.

May 18, 1954 `s. PHlLlBoslAN x-:TAL

SANDING MACHINE 11l Sheets-Sheet 6 Filed April 19, 1950 INVENTORS auna?l?. @0M/E BY WILL/AMJ 570m; Ano

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May V1 8, l 9 54 SANDING MACHINE 11 Sheets-Sheet 7 Filed April 19, 195:

May 18, 1954 s. PHILIBOSIAN Em, 2,678,522

` SANDING MACHINE Filed April 19, 1950 l1 Sheets-Sheet 8 414 L 37 l l 3Il.' 37a Ifu fly f6' "l 3 372 u 33 an' u '72 30300 312 35a aa 380 p 2 L328 332 q r.:-

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May 18, 1954 SANDING MACHINE 11 snears-sneet 9 Filed April 19, 1950WILL/AM J. .sroP anw 2 JNVENToRs @LIVER R. ROWE 5 TEP/ff PH/l 0505 IAN@MM/KM A Traer/Er.:

May 18, 1954 s. PHlLlBoslAN :TAL

SANDING MACHINE Al1. Sheets-Sheet 1G Filed April 19, 1956 l JNVENTORSoL/rf .4?. Paws,

BY WML/AM J: .STOLR AIVD ATTORNEYS May 18, 1954 s. PHlLlBoslAN Erm.2,678,522

sANnING MACHINE Filed April 19, 195o 11 sheets-sheet 11 536 `5m 5,6f1.9. Z3

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f @if 502 f2? MWWHIIMWif 1 6 mum . INVENTORS mJrc-AP A. Rows, w/LL/AM.-r. .s1-uP No BY .sume/v nm asas/AN Patented May 18, 1954 UNITED STATESPTE QEFlCE SANDING MACHINE Stephen Philibosian, Oliver R. Rowe, andWilliam J. Stolp, Charlotte, N: C., assignors to R. H. Bouligny; Inc., acorporation of North Carolina Application April19, 1950, Serial N o.156,778

11 Claims.

ticularly well adapted for sanding woodwork having an irregular surfacecontour such as molding and the like, and in which the work is -fedthrough the machine ina manner that results in exceptionally high speedoperation.

According to the present invention a particularly advantageousarrangement is provided for disposing the endless sanding belt forapplication to the work to be sanded. Generally described, thisarrangement comprises a driven pulley and an idler pulley disposed onthe machine in spaced relation for carrying the endless sanding belt,and a pressure pad disposed intermediate these spaced pulleys forapplying the sanding belt to the work to be sanded. The idler pulley isdisposed according to this arrangement so that it is `adjustablelongitudinally With respect to the reach of `the endless sanding beltand pivotally on an axis aligned with the medial cross-section of theidler pulley, so that the idler pulley is readily adjustable not onlyfor regulating the slackI in the sanding belt but also for truing ortracking the sanding belt on the pulleys, and'iurther for allowing thesanding belt to be removed readily when desired. Also, one or both ofthe sanding belt pulleys` (usually `the driver pulley at least) are` atthe end opposite to the end at which the workto be sanded is fed, sothat slack is induced in the endless sanding belt between the drivenpulley and the pressure pad for facilitating application of the endlessbeltby` the pressure pad in conformance with the `contour of the work tobe sanded. This operation of the driven pulley to` drive the sandingbelt ,oppositely to the direction of work feed also providesV theimportant advantage of maintaining an end to end relation oi theworkpieces as` they are fed beneath the sanding belt.

A further feature of the present invention is the arrangement of asupporting arni for the pressure pad which is pivoted` on a horizontalaxis to allow the pressure pad to be lowered or raised for applicationor release` of the endless sanding belt, and which is disposed with apivoted extent in raised position substantially parallel with the lineof travel of the sanding belt,l

so that adequate clearance is provided for disposition and applicationof the pressure pad between the working and return reaches ofthe sandingbelt by pulleys no larger than are necessary for carrying the sandingbelt to the best advantage. In addition, the pressure pad is uniquelymounted on the supporting arm so that it is free to float in alldirections in order to nd its proper position when lowered for workingcontact with the work to be sanded, While at the same time beingcontained in longitudinal alignment with the line of travel of the work.

The supporting arm carrying the pressure pad is also formed with apivoted joint having an axis disposed at right angles to its horizontalpivot axis so as to allow lateral movement of the supporting arm, andthis pivoted joint is arranged so that its axis is positionedsubstantial- 1y vertically when the supporting arm is disposed toposition the pressure pad at its farthest downward extent. With thisarrangement, the axis of the pivoted joint is always inclined from thevertical whenever work is fed beneath the sanding belt, so that anyforce tending during the sanding operation to move the pressure padlaterally out of line will cause movement of the supporting arm toresist this force, with the result that application of the pressure padis rendered inherently stable.

The sanding machine of `the present invention is also equipped with afeed table for maintaining a supply of work in position for feedingthrough the machine, and which is arranged to insure that no stoppage'or gap occurs in the flow of work through the machine. This feed tablecomprises a conveyor belt and associated guides arranged to channel thework in line from the reed table, and a gate member disposed in relationto these guides so that only one work piece can pass from the feed tableat a time, which makes it possible to place the work pieces rapidly onthe feed table without precise arrangement so long as they are restingon the conveyor belt. In addition, this feed table is arranged so thatthe mounting pulleys for the conveyor belt may be easily manipulated forremoval and replacenent of the conveyor belt when necessary. Beyond thefee-d table, the machine is further equipped with bottom and top feedrolls, both of which of are driven for feeding the Work beneath thesanding belt, but which are nevertheless adjustable 'for spacing asnecessary to handle various sizes of work to be sanded.

These and other features of the present invention are described furtherbelow in connection with the accompanying drawings, which:

Fig. 1 is a fragmentary front side elevation oi the feeding end of asanding machine constructed in accordance with the present invention;

Fig. 2 is a complementary front elevation of the, remaining portion ofthe machine shown in Fig. 1;

Figs. 3 and 4 are fragmentary plan views corresponding to Figs. 1 and 2,respectively;

Fig. 5 is a rear elevation of the main portion of the sanding machineshown in Figs. l to 4;

Fig. 6 is an enlarged side elevation detail of the idler pulley andrelated operating elements;

Fig. 7 is a View in plan corresponding generally to Fig. 6;

Fig. 8 is a detail, largely in section, as viewed substantially from theline 2--8 in Fig. o;

Fig. 9 is a sectional detail taken substantially on the line 9 9 in Fig.7;

Fig. 10 is an enlarged side elevation detail of the driven pulley andrelated operating elements;

Fig. 11 is a corresponding end View from the right as seen in Fig. 10; Y

Fig. 12 is a partial detail in plan corresponding generally to Figs. 10and l1;

Fig. 13 is an enlarged side elevation detail of the means supporting thepressure pad used for applying the endless sanding belt;

Fig. 14 is a detail in plan corresponding gen erally to Fig. 13; f

Fig. 15 is a sectional detail taken substantially on the line l-i inFig. 13;,

Fig. 16 is a detail largely in section, as viewed substantially from theline ie-i e Fig. 13;

Fig. 17 is a sectional detail taken substantially on the line i'l-ii inFig. 14;

Fig. 1S is a sectional detail taken substantially on the line l-i inFig. 14;

Fig. 19 is an enlarged side elevation detail of the feed'means andrelated operating elements;

Fig. 20 is a sectional detail taken substantially on the line 2li- 2d inFig. 19;

Fig. 21 is a sectional detail taken substantially on the line 2i-2i inFig. 20;

Fig. 22 is an illustration, mainly diagrammatic, corersponding generallyto Fig. 19 and illustrat ing the driving arrangement for t .e feedmeans;

Fig. 23 is an enlarged fragmentary detail in plan of the feed table;r

Fig. 24 is an end elevation of the entire feed tabletaken from the rightin relation to Fig.

Fig. 25 is a fragmentary side elevation of the extending end portion orthe feed table;

Fig. 26 is a fragmentary detail in plan illustrating the arrangement ofguide means beneath the pressure pad for directing' work to be sanded;

Fig. 27 is a fragmentary detail in side elevation correspondinggenerallyto Fig. 26; and

Fig. 28 is a sectional detail taken substantially on the line 28-28 inFig. 26.

Referring now in detail to the drawings, and in particular at first toFigs. 1 to 4, the sanding machine ofthe present invention' as showncomprises a frame structure S arranged to form a sanding bed forsupporting Work to be sanded, a drivenpulley D and an idler pulley Idisposed on the frame structure S in spaced relation for carry ing anendless sanding belt B, feed means F for feeding work to be sandedbeneath the endless sanding belt B, means for securing guide members inplace as at G on the frame structure S for directing the work fed forsanding longitudinally oi the reach of the endless sanding belt 13,'

a pressure pad P disposed on the frame structure S intermediate thespaced pulleys D and for applying the endless sanding belt l5 to theWork, and a feed table T arranged for maintaining a supply of Work to besanded at the feeding means F.

The frame structure S maybe arranged in. any suitable manner forsupporting the operating elements of the sanding machine as may beindicated or required in particular instances. As shown in the drawings,it is formed with an en closed base portion ie iitted appropriately withan access door as at i 2 for providing a convenient storage space toaccommodate tools and maintenance supplies and the like such as may beneeded in operating the sanding machine. The frame structure S is alsopreferably formed with an upper hood portion is arranged with at leastone fitting as at i@ for attachment to suction recovery line to carryoff the 4dust produced during the sanding operation. Y

This hood portion i4 is open at the front, and may be similarly open atthe back to the extent desired, to permit the necessary supervisionor"the sanding operation, and to allow manipulation and adjustment of theoperating elements readily by an operator. The hood portion iii alsoformed With openings at each end to allow work to be fed through themachine on the sanding bed formed by the top of the base portion it, thebase portion il) is :fitted at this point with a plurality of spacedclamping arms I8 comprising (as shown in detail in Fig. 18) arm membersE@ pivoted on fastening screws 22 and spacer bushi ings 24, and carryingclamping screws 25 at their extending ends which'are formed with pointedtips as at 26 for securing the previously mentioned guide members G forthe Work being sanded in place.

These guide members G may be arranged to the best advantage in mostinstances by forming them specially, vin the nature of a to form guiderails providing a closely fitting channel for handling the particular.form of Work to be sanded.V Generally, they will consist of front andrear guide pieces as at 2i! and t@ (see Figs. 26, 27 and 28) to channelthe Work as at W longitudinally beneath the sanding belt B,Y and usuallya specially adapted support piece as at 32 arranged directly beneath thepressure pad F for providing a free path for the sanding belt B so thatit may run in contact with the full contour of theY Work W to be sanded,which in molding contours will often extend to a bottom edge of the workW (compare Fig. 28)..

As the guide members G must thus be fitted to meet the specialrequirements of the Work W being handled, they can usually be installedmost conveniently by forming themY of wood, Which can be Worked easilyto the form desired, and the clamping arms i3 provide an excellent meansfor fixing the wood pieces forming the guide members G in place in theVariety of arrangements that may be required. Also, it should Vbe notedthat the sanding bed formed by the top surface of the base portion i@or" frame structure S is undercut as at tl so as to allow .a speciallyadapted guide support piece 3E as mentioned above to be clamped in placebeneath the pressure pad P in line with the guide pieces 28 and 30 andlevel with the remainder or the sanding bed. The work W after sandingissues from` the guide members G onto an end table mounted on the framestructure S as at Sii, and from which the sanded work may be removedconveniently as the sanding operation is carried out.

As already noted, the sanding belt B is carried on the framestructure Sby the driven pulley D and the idler pulley I.` The drivel' pulley D isdisposed on the frame structure S at the end opposite from the feedmeans F for a purpose which will be describedmore in detail presently.The idler pulley I is disposed at the ether end ofthe frame structure Sadjacent the feed means F, and is mounted on the frame structure b abracket assembly lll!! as shown in detail in Figs. 6 to 9 of thedrawings.

This bracket assembly |90 comprises a support post M32 formed at itsupper end for carrying a stub shaft lll on which the idler pulley ismounted for rotation by bearing units as at ||l|3 tted in the pulley hub|53 and xed in spaced relation to the stub shaft HB4 between a retainingring and a locknut ||2 (see Fig. 8). The lower portion of the supportpost I 32 is arranged for sliding adjustments in a bracket member ifithat is tted with a clamping plate |56 `which may be tigl'ltened` downby screwsV ||8 to grip the post |ll2 against movement in the bracket I4, but which is formed with a bored and tapped lug |20 through which anadjusting stud |22 extends from the lower end of the post ||l2(compareFigs. 6 and 8). The lower tip of this adjusting stud |22issquared ol as at |24 to `.receive a, wrench or the like so` that, uponloosening the clamping plate HB, theadjusting stud |22 may be turned forraising or lowering the idler pulley I to a desired adjusted heightabove the sanding bed formed by the frame structure S.

The bracket member lle carrying the support post |02 is in turnassembledon a bottom slide base |26 which extends beneath the sanding bed formedby the frame structure S for` disposition against the bottom faces offront andrear slide bars |28 and |39 carried on the frame structure S.This bottom slide base |25 is formed to receive `a central pivot pin |32which is aligned vertically with the axis of the idler pulley I at itsmedial cross-section, and which is mounted in a top slide base |34 thatis grooved to ride on top of the frcnt and rear slide bars land |39.

The lower end of the pivot pin |32 is threaded i for locknuts as at |36,which may be tightened up to the proper` extent against a spring |38disposed over the pivot pin |32 `below the bottom slide base |25 toclamp` the bottom and top slide bases |2 and |545 onthe front and rearslide bars |23 and |39 securely against casual movement, while stillleaving them free enough for` longitudinal adjustment on the slide bars|23 and |36 as explained further below.

of the frame structure S on a transverse shaft This transverse-shaft |62istted with a bevel gear as at |44 disposed for engage* shaft M2.

mentwith a mating bevel gear |46 mounted at one end of a traverse screw|48 that extends fer4 6 l threaded engagement with the top slide base|34 as at |50, a bracket |52 being secured on the frame structure S forsupporting the traverse screw |48 and the transverse shaft |42, asshown,

5 with the bevel gears |44 and M5 in running engagement. Thisarrangement provides a relatively great mechanical advantage allowingeasy longitudinal adjustment of the idler pulley l from the handwheel|49, while at the same time permitting the bottom and top slide bases|26 and It@ to be clamped tightly on the slide bars |28 and |30, asmentioned above, so that the idler pulley l will remain securely inplace at any longitudinally adjusted position selected.

Pivoted adjustment of the idler pulley I, as already noted, is alsoprovided by the above described arrangement of the bottom and top slidebases |26 and |343 by which the pulley I is carried on the framestructure S. This pivotal adjustment is made about the central pivot pin|32 which, being vertically aligned with-the axis of idler pulley at itsmedial crcss-seetion, allows the pivotal adjustment to be madeindependently for truing or tracking the sanding belt B on the pulleys Dand I without affecting the slack in the belt B attained at a givenlongitudinal adjustment of the pulley l.

at the trant of the .frame nounted on a screw shaft ing engagement withboth base i3d is formed fer this with a lateral arm portion n. a besswhich is bcred tc receive a itiwith the shank of the pin |69 and in turnbored to receive the screw freely for rotation, The screw shaft.,ltioned at this pivot pin id@ by a spacfor threaded enga as at iddwhich cw ried in a pair of bracket plates secured en top and bcttomlaces ci the bottcm slide base ir, and a spring |68 is disposed over thescrew shalt 55E between the pivet pin it the adjacent edges of thebracket plates result or this arrangement is that the spring maintainsspacing cellar |52 in abutting rel on with the first pivct pin itil atall times w le allowing the second pivot Din iifi to be taken up cr letcli on the screw shaft ld as the slide |34 is grcoved to ride on top ofthe slide bars and iii@ and is thereby -ixed against pivotal movement,ad justment ci the second pivot pin lil!! in this inanner on the screwshaft |555 causes pivoting of the bottom slide base |26 about thecentral pivot pin which. effects 'ite pivoting of the idler ,nulle l ferangular adgustinent as desired from `the ting knob 55d.

The driven pulley l spaced on the idler pulley inculate7 electric motore structure S on s. 57 l0, l'l l2).

bracket assembly comprises a motel' 2; .i ed a mounting plate 265| by fThe mounting plate 2:38 is the :fram c e S as at arranged to be teneddawn normally by screws at 2m for hol ng the motor bracket 2st in iixedrelation which as noted above 1s ucture S in relation to the forcailylng the belt E, is

gement with second pivot pin on the mounting plate However, these slideclamps 2i@ are further arranged for allowing vertical adjustment of themotor bracket 293B on the mounting plate Zut upon loosening of thescrews 2 i4. To regulate this vertical adjustment, which is provided toallow the height of the driven pulley D above the sanding bed formed bythe frame structure S to be adjusted similarly to the idler pulley I,the motor bracket it is tted with an adjusting stud 2HE having a.squared lower tip portion adapted for receiving a wrench or the like, asin the case of the stud E22 provided for idler pulley I. This adjustingstud 2M extends upwardly for threaded engagement with a lug iixed as at22S on the upper portion of the mounting plate 2%8, the motor bracket2135 beine' slotted as 22? to clear the lug as it is raised or loweredon mounting plate tilt to adjust the driven pulley D at a desiredheight.

It shou also be noted at this point that, as previously mentioned, thedriven pulley D is dis posed on t s'- `ucture S at the end opposite toat ich the work W is fed beneath the can; and further that theV drivenpulley D is operated to drive 'the sanding belt VB in a directionopposite to the direction in which the work W is fed for sanding, asindicated by the directional arrows in Figs. land 2. rlhis arrangementand manner of operation of the driven pulley D resuits in inducing slackin the sanding belt B between the pulley D and the pressure pad P, whichis a particularly advantageous feature when the work W being sanded hasan irregular surface contour because this slack'induced ahead of thepressure pad P substantially facilitates the appli.- cation of thesanding belt B by the pressure pad P in conformance with the irregularcontour of the work W.

For this same general purpose, it has long been common practice to worklongitudinal creases in an endless belt of the type represented by thereference character B in order to condition it for breaking or foldingsharply in a widthwise direction to reach satisfactorily sharp angularpoints inthe surface contours of the work being sanded. This expedientis o1" material aid in carrying out standing operations generally aswell as with the machine of the present invention. It involves onetroublesornD difficulty, however, in that a sanding belt B that has beenlongitudinally creased for this purpose has a tendency to fold uponitselrn as it runs so that it cannot be maintained :flatly extended tofull width over the pulleys D and I en which it is carried, and for thisreason the extent to which advantage may be gained by longitudinallycreasing the sanding belt B is normally, as a practical matter,seriously limited.

This difficulty is greatly reduced according to the present invention byarranging auxiliary idler rolls in relation to one or both of thesanding belt pulleys D and l to run in contact with the face of thesanding belt B just before it is taken over these pulleys D or I. Anauxiliary idler roll is shown at 224 arranged in this manner in relationto the driven pulley D. This idler roll 224, as shown, is mounted forrotation in bearing units as at 226 which are carried on a supportingarm 228 that extends from a vertical pivot shaft 23S disposed at therear oi the frame structure S.

VrEhe supporting arm 222i is keyed on the pivot shaft 231i as at 232,and formed with a split hub portion 231i for clamping adjacent the upperend of the pivot shaft 235 at al desired vertical position in relationto the driven pulley D.

The pivot shaft23 is in Vturn supported for` pivoting movement in boresof spaced bosses formed as at 235 on Va mounting bracket 238 that issecured as by screws 240 on the driven pulley mounting Vbracket 268.retained in the bosses 236 of mounting bracket 238 by an adjusting arm252 having a hub 2M fixed on the pivot shaft 23e above the bosses 236,"

and a spacing collar 246 similarly fixed below. The adjusting arm 242extends from the pivot shaft 230 below the supporting arm 2278 towardvthe front of the frame structure S, and the mounting bracket 233 alsosupports in 'lxed relation an adjusting arm bracket 248 that extendsadjacent the adjusting arm 262. The extending ends of both the adjustingarm 242 and adjust- Ving arm bracket 2M are fitted with pivot pins as at25? and 252, respectively, formed to receive an, adjusting screw 254carrying a manipulating f knob as at 256. The pivot pin 2 52 in theadjusting arm bracket 2da receives the adjusting screw` 251i freely,while the pivot pin 259 in the adjust` ing arm 242 is threaded to engageits extending end, and a spring 25o is disposed over the acl--v l arenot disturbed duringY any vertical adjustment of the pulley D. Also, asnoted above, the idler roll 224 is independently adjustable on the pivotshaft 23u in relation to thepulley D. Usually, the, idler roll 221ishould be positioned Vwith it bottom surface somewhere on theorder ofabout 1%,"

below the top surface of the pulley D. With this relative disposition,the sanding belt BY is subjected to a reverse bending as it isntakenover the idler roll 224 onto the pulleyV Dwhich main-,

tains it flat in a very effective manner even when a substantial amountof longitudinal creasingris present in the belt B. An auxiliary idlerroll 224 of this sort may also be employed to good eiect for guiding ortruing the sanding belt B on the pulleys D and I by making it pivotallyadjustable A through an adjusting arm 242 and an adjusting arm bracket24B as described above.

An auxiliary idler roll may similarly be arranged as at I in relation tothe idler pulley I,

if desired. In most cases an idler roll 224 at the i driven pulley D isenough, but a second one may advantageously be prvided at the idlerpulley I too, for use when needed. The idler roll i'i at the idlerpulley I might be exactly like the driven pulley idler roll 224 as justdescribed, but where a pivotal adjustment is provided for the pulley Idirectly, then the idler roll HS need only be mounted for rotation on asupporting arm |72 carried by a bracket |14 having a split hub as at lltadapted for clamping on the pulley shaft 104 j to dispose the idler rollil at a proper Voperating position in relation to the idler pulley I, orat an inactive position clear of thesanding belt B when not needed. Y

The pressure pad P by which the sanding belt B is applied to the work W,as already mentioned, is disposed according to the present inventionb`etween the working and return reaches of the endless sanding belt B atthe extending end oi a supporting arm Stil, which is carried on thetrame structure S for pivoting movement about a horizontal axis Vtoallow the pressure pad P to be lowered or raised for applying thesandingV belt B to the work W or releasing it as desired. VAn iin-- Thepivot shaft 23!) isV portant feature of this arrangement of thesupporting arm Iiil is that in raised position it is "disposed with apivoted extent substantially parallel to the line oi' travel of thereaches of the sanding belt B so that `adequate clearance fordisposition and application of the pressure pad P is provided betweenthese reaches by driven and idler pulleys D and I which are no largerthan are necessary for carrying the endless belt B to the beetadvantage. For example, a sanding machine may be constructed accordingto the present invention with driven and idler pulleys D and I having adiameter of only about 8 inches which will handle work W up to about iinches in thickn ness, and which allow a wellebalanced design for themachine and nia-ke it possible to correlate the size of the drivenpulley D nicely with the drivthe horizontal pivot axis, and furtherarranged that this lateral pivot axis ispositioned substantiallyvertically when. the supporting arin Stil `is lowered to position thepressure pad at its farthest downward extent, i. e., directly on theframe structure S with no work W disposed beneath the sanding `belt`Accordingly, when `work W is fed beneath the sanding belt B, so that'the supporting arm @to must be positioned above its farthest downwardextent, this lateral pivot axis will be inclined backwardly from the`vertical so that any lateral movement of the `supporting arzn teli willcause the pressure pad P to be applied `with greater force against thesanding B which, together with the gravity force on the pressure pad P,will set up a inoment about lateral pivot axis tending to return thesupporting arm {ist} to normal position. As a result any force exertedby the work W during the `sanding' operation which tends to move thepres `sure pad P laterally out of iine Vwill be resisted by `thisdisposition of the supporting arrn Zilli), s that the application of thepressure pad P during the sanding operation is inherently stabilized.

With more particular reference to the structural forro and dispositionof the supporting arm tot, which is illustrated in detail in Figs. 13,le and l of the drawings, the horizontal pivot axis `for he supportingann Silii is formed by a tubular pivot shaft which is carried in amounting bracket arranged at the rear of the frame structure E, with'the pivot shaft 362 free for `lateral sliding movement as well asrotation, as will appear more indctail presently.

The supporting arrh tilt proper comprises two principal structuralelements 39S and illl which yare assembled at a pivot pin 3i@ formingthe previously mentioned lateral pivot axis. The first element tilt isformed with a hub portion SI2 at `which it is tted over and fixed on thepivot `shaft S92, and is otherwise arranged in the nature of `a yoke orclevis for receiving the pivot pin Sli) and with the upper portion ofthis yoke-like structure extending as a covering apron over the secondelement But. The second element Bilt con- `ssts of an arm ineniber whichextends from the pivot pin il!!! under and beyond the covering apronportion of the rst element 39S to carry a mounting bracket tie for thepressure pad P. The covering apron portion of the rst element i396 isfurther fitted adjacent its extending end 'with adjusting screwstitarranged to bear oplil positely on springs @i8 disposed at each side ofthe second element or arm member tilt for maintaining it normallybalanced at a centrally aligned position, although allowing it to shiftlaterally when necessary during the sanding operation.

The arrangement of the horizontal pivot shaft on which the supportingarrn its is carried is illustrated best l5 of the drawings. As shown,this pivot shaft is tubular in form, and is assembled concentrically ona screw shaft .320 between front and housing collars as at 322 and'siii-t, which are disposed freely on the screw shaft 32e, but which areretained in iixed lateral relation for supporting the pivot shaft Sii?by an adjusting knob pinned on the screw shaft 32e at its front end, andan hexagonal-shaped collar li' pinned on the screw shaft 320 adjacentrear end. The pivot shaft 302 is slidingly supported as at 33t in abored boss formed on the mounting bracket tile, while the screw shaftfait on which it is assembled extends further rearwardly for threadedengagement with an opstanding lug 332 also formed on the mountingbracket tilt in spaced relation with respect to the boss 339, thepreviously mentioned rear housing collar 32d and the hexagonal-shapedcollar being arranged on the screw shaft 326) between the boss @its andthis upstanding lug 332.

rlhe rear housing collar 32e is additionally forined with spaceddepending lugs 33t disposed for straddling the adjacent portion ofmounting bracket 361i, and with a laterally extending boss which isbored to receive and position a spring 338 and plunger 3st between thisportion of the bracket 3FM and the previously mentioned hexagonal-shapedcollar 32u fixed on the screw shaft The spaced lugs 32 prevent the rearhousing collar from turning with the screw 329, and the spring 338 andplunger 34B are provided to .maintain the screw shaft 326 at a givenlateral position, the hexagonal-shaped collar 328 being employed topresent a series of bearing faces for the plunger Silo, against one ofwhich the spring 328 yieldingly presses thc `plunger 313i] to resistturning of the .screw shaft 32e except under turning pressure exertedfrom the adjusting knob 32d. it will be seen that turning of thescrewshaft will result in advancing or withdrawing it at the lug 3552 onbracket 3M,

which will in turn result in lateral adjustment of the pivot shaft to2and the supporting arrn` 300 it carries for supporting the pressure padP.

For raising and lowering the supporting arm 365i in order to shift thepressure pad P between operating and inactive positions, la cam shaft342 is carried in lateral arm portions 34d formed on the boss 33|] ofthe mounting bracket 04. This cani shaft 3fl2 is fitted at itsforward-end with an operating' arm 3st arranged conveniently `at thefront of the frame structure S, and carries ,a cam clement fille at itsrear end in relation to a cani follower bracket 3th xed on the pivotshaft 362. The cam follower bracket 35@ is formed with an extending arznportion 352 fitted with `a laterally disposed follower element 354 atits extending `end for following the cano element 3ds in variouslaterally adjusted positions of the pivot shaft 332 `and supporting armtile. The cam element i348 may accordingly be controlled from the `operw,ating arm 345 for raising `the supporting armill! or releasing it tolowered position for application of the sanding rbelt B by the pressurepad P as desired.

'In order to regulate the pressure with which the sanding belt B isapplied by the pressure pad P, the supporting arm 306 is further fittedwith guideways 336 for carrying weights as at 353. The guideways 356 aresecured on the supporting arm'303 at the hub portion 392 of the firstelement 303, and adjacent the extending end of the covering apronportion of the element 336, so that they allow a range of adjustment ofthe Vweights 353 in relation to the horizontal pivot axis of thesupporting arm 360 for varying the pressure with which the pressure padP is applied. The guideways 356 are also extended rearwardly to formcounterweight balance arms as at 366 for supporting a counterweight (notshown) in instances where the pressure with which the :pressure pad P isapplied needs to be counterbalanced. The counterweight balance arms 366extend from the hub portion 32 and are slotted as at 362 to provideclearance for the cam shaft 342, and are further tted with a cross brace364 at their rear ends.

The pressure pad P, as previously mentioned, is carried in a mountingbracket 314 at the extending end of the arm portion element 363 of thesupporting arm 306. This mounting bracket 3M has a clevis form arrangedfor carrying a pressure pad holder 366 at a clevis pin 333. The pressurepad holder 366 has a spider form composed of arm portions extendinglaterally to each side and frontwardly and rearwardly from its point ofsupport at the clevis pin 363, and in each of these arm portions plungersleeves 336 are arranged to carry spring positioned plungers 312. Thepressure pad holder 363 is also formed with a depending nange 374 at theextending end of its rear arm portion, which is fitted with asemicircular bracket 316, and dependingr iianges l313 formed withinwardly extending bottom edges as at 386 to form an undercutlongitudinal slot are arranged substantially centrally of the holder366. A mounting plate 332 is provided for carrying the pressure pad Pdirectly, and this mount- .ing plate 382 is formed with two upstandingballpointed studs as at 384 and 386. The ball stud 384 is disposedcentrally of the mounting plate 382 and is thereby arranged for fittingin the longitudinal slot formed by the flanges 373, while theball-pointed stud 386 is arranged for disposition in the semicircularbracket 3'6 behind the depending ange 3'14. By this arrangement, thebearing point of the ball-pointed stud 336 on the rear ange 314constitutes the only means by which themounting plate 382 is heldlongitudinally in the holder 366, the ball-pointed stud 384 merelyserving the purpose of maintaining the longitudinal alignment of themounting plate As a result, theY mountingplate362 is carried in theholder 30E so that it is free to float in all directions, althoughalways fully restrained in longitudinal alignment, and is further easilyremoved from the holder 336 for changing pressure pads P. The pressurepad P carried by the mounting plate 382 will, of course, beappropriately adapted for applying the sanding belt B to the work W andmay take any conventional form.

' It should also be noted that the mounting bracket 364 for thesupporting arm 360 carrying the pressure pad P is secured on the framestructure S by a mounting plate 338 and slide clamps 330 in a mannersimilar to the mounting arrangement of the driven pulley D, the mountingbracket v304 being tted with an adjusting stud as at 392 for threadedengagement with a lug arranged as at 394 on the mounting plate 388.

The feed means F, Which is provided for feeding work beneath the sandingbelt B is illustrated in detail in Figs. 19 to 22. This feed means Fcomprises a bottom driven feed roll 430 and an overhead pressure wheel402 which is also driven. The bottom feed roll 400 is carried on a shaft404 which is journaled on the frame structure S, and which may be drivenin any convenient manner, such as by an electric motor 406 connected bybelt or sprocket chain drives 403 and 410 through a gear box 412 to apulley or sprocket wheel 414 carried on the bottom feed roll shaft Y Theoverhead pressure wheel 402 is provided to maintain the Work in contactwith the bottom feed roll 400 for effective feeding action, and for thispurpose is mounted for vertical adjustment in a support housing 413 xedat the rear of theframe structure S, the stub shaft 413 carrying thepressure wheel 462 being journaled in a bearing 420 which is slidinglyarranged in a vertical guideway as at 422 in the front face of thehousing 416, and which is tted with a cap plate 424 extending inside thehousing 41B and formed with a threaded opening for engaging an adjustingscrew 426 vertically disposed in the housing 416 for manipulation from ahand wheel 428 at its top end.

In order to provide for driving the pressure Wheel 402, the stub shaft418 is arranged to extend through the bearing 420 for supporting a bevelgear 430 in engagement with a mating bevel gear 432 slidingly keyed on avertical shaft 434 also carried by the housing 416. This mating bevelgear 432 is assembled for rotation in the cap plate 424 fitted on thebearing 420 for the pressure wheel stub shaft bearing 418, so that it ismaintained in engagement with the bevel gear 433 on stub shaft 418 atall vertically adjusted positions of the pressure wheel 402. A secondbevel gear 436 is keyed on the vertical shaft 434 at its lower end toengage a mating bevel gear 43S carried at the rear end of the bottomfeed roll shaft 404, so that the vertical shaft 434 is driven from thebottom feed roll shaft 404 and in turn drives the pressure wheel stubshaft 418. This feature improves the feeding action at the feed means Fsubstantially because the drive for the overhead pressure wheel 402results in drawing the work into the nip of the feed means F much morereadily than when only the bottom feed roll 400Y is driven, and itfurther provides for handling special forms of work with which adequatefeeding'contact can be had only at their top surfaces. In thisconnection, it should be noted too that the overhead pressure wheel 462is arranged for lateral adjustment on the stub shaft 418 by opposed jamnuts as at 440 to position it properly for feeding contact with thework. Means for speed adjustment at the feed means F, and for the feedtable T which is described further below, is provided from a handwheel442 arranged at the front of the frame structure S for adjustment of thevertical position of the motor 466, through shaft 444 and an adjustablemotor base mounting 446 connected by bevel gears as at 448 and 450, toactuate a variable speed motor pulley 452.

As previously mentioned, a supply of the work to be sanded is maintainedat the feed means F by a feed table T as shown generally in Figs. 1 and3 of the drawings, and illustrated more in detail in Figs. 23 and 24. Asshown, this feed `rear mounting pulleys elle and 5635. mounting pulleyelle is fitted for rotation on a housing frame by.F

`poratiilg spherical shaped bus table T comprises a housing frame 50D:secured Non the frame structure S to extend at the feeding end forcarrying a conveyor belt ii?. on front and The rear shaft formed withflat-sided ends which are carried in the housing frame Bild byhorizontally slotted mounting blocks iilil adapted to receive thefiat-sided ends of the shaft et. In this manner, the sha-it ismaintained against `rotationin the mounting blocks 5i@ but is free ,forsliding adjustment for tightening the conveyor belt titi properly. Thissliding adjustment is provided for by screws 5i?. fitted laterally inthe shaft des adjacent itsends to bear on abutment lugs 51d formed onthe mounting blocks 5H), and thereby space the shaft in the mount- :ingblocks fait to obtain the belt tightness desired `l't should `be noted,however, that the shaft its is held in the mounting blocks 510 only bythe pull of the conveyor belt 5F52, and that it accordingly may beremoved from the nply sliding it rearwardly out of the mounting blockstit Whenever the conveyor belt is loosened for removal.

In order to provide for i moving the conveyor belt ddii with equal easeat the front mounting vpulley Silit, the shaft Edil on which this irontpulley 55s is fixed is .mounted in bearings 528 and 52d at the front andrear ci the housing frame 5t@ which are of the seh-aligning type incor-^ings as indicated by dotted lines at dit and 52 to support the shafte36. The front bearing titi? is mounted inside the housing frame ddii sothat its mounting `screws 522 are readily accessible at the front faceof the housing` frame 59e, While the rear `bearing eilt is mounted onthe bacia lace of the housing frame to space it as far as possible fromthe .trontbearing dit?. With bearings of this type arranged in. themanner just described,

it is possible by simply removing the mounting screws 522 to free theiront bearings lS from the housing frame and then to pivot the shaft 5l@about its point of support in the rear bearing dit? by reason oi thespherical shaped bushing which this bea 1ing contains, as mentionedabove, and thereby dispose the front mounting pulley angularly, asindicated by dotted lines in Fig. 23, so that the conveyor belt 5&2 maybe slipped off of its free end and removed `easily with the rearmounting pulley li for replacement when necessary.

When in place, the conveyor belt till?. is driven iat the iront mountingpulley 581i through a belt ,or sprocket drive 52d running from thepreviously mentioned gear box lili at the feed means F lto `the frontpulley shaft 5i 6 (see Fig. 22).

The housing frame 5de is further fitted `with riront and rear guidemembers 528 and 525i for :channeling the Worli on the conveyor belt 5M'to the feed means E'. The rear guide member )52B consists of anupstanding guide ange of substantial height which extends forsubstantialthe entire length of the feed table and which is carried onthe housing frame 5t@ by pivoted :arms 53h which allow it to be spacedover the `conveyor belt est as desired, The front guide `member 526consists of an upstanding flange of frame Stil for angular dispositionadjacent the forward end of therear guide member 528 for .directing theWork against the rear guide inem .ber ilas it is advanced forwardly `onthe lcon- `said frame i structure veyor belt 502. Beyond the forward endof vthe also carries a gate member 53d which consists of a verticallydisposed plate arranged for sliding adjustment in a slide clamp 535 sothat its lower edge may be adjusted above the level of the conveyor belt5B?! in accordance with the thickness of the Work being .handled forallowing only one .piece of work at a time to pass onto the feed meansF. With front and rear guide members 525 and 528 and a gate member 53darranged in this manner, it is possible to adjust them in relation tothe size and form of the Work W oeing handled so that pieces of the WorkW may be placed on the feed table T in a very rapid manner Withoutparticular attention to their precise arrangement other than to seethatitney are resting on the conveyor belt db2.

We claim:

1. A. sanding machine particularly adapted :for sanding Woodwork havingan irregular surface contour such as molding and the like, said machinecomprising a frame structure, a `driven pulley and an idler pulleydisposed on said traine structure in spaced relation for carrying anendless sanding belt, means disposed at one end of said frame structurefor feeding work to be `sanded beneath the endless sanding belt longietudinally of the reach of said belt, and a pressure pad disposed on saidframe structure intermediate said spaced pulleys for applying theendless sanding belt to the work to be sanded, saiddriven pulley beingoperated to drive said endless belt for application to the Work in adirection opposite to the direction in which the work to be sanded isfed and being disposed on said frame structure at the end opposite tothe end at which the Work to be sanded is fed, whereby slack is inducedin the endless sanding belt between said driven pulley and said pressurepad for facilitating application of said endless belt by said pressurepad in conformance with the contour of the Work to ibe sanded, and idlerpulley being adjustable on said frame structure vertically andlongitudinally with respect to the Ireach of the endless sanding beltand pivotally `onan axis coincident with the medial crosssection of theidler pulley, whereby said `idler :pulley may be adjusted for regulatingthe slack in said endless belt and for truing the belt non said pulleyswithout disturbing the slaclrregulation of said belt.

2. A sanding machine comprising a vframe structure, a driven pulley andan idler pulley `disposed on said frame structure in spaced relation forcarrying an endless sanding belt-and a pressure pad arrangedintermediate said spaced `pulleys for applying the end ess sanding `beltto Work to be sanded, said pressure pad being mounted on a pivotedsupporting arm carried by for pivoting movement about a horizontal axisextending' transversely `between the Working and return reaches of saidendless belt, and said supporting arm being further formedwit'n apivoted joint adjacent the point of pivoted support on said framestructure, the axis of said pivoted joint being disposed at Yrightangles to said horizontal pivot axis and being positioned verticallywhen said supporting arm is disposed to position the pressure pad at itsfurtherest downward extent.

3. A sanding machine comprising a frame structure adapted to supportWork to be sanded,

a driven pulley and an idler pulley disposed on csaid frame structureinspaced relation for carpulley, a first adjusting means for shiftingsaid slide bases longitudinally on said guideways for regulating slackin said endless sanding belt, and a second adjusting means for pivotingsaid bottom slide member with respect to said top slide member fortruing said endless sanding belt on said pulleys without disturbing theslack regulation of said belt.

10. A sanding machine comprising a frame structure, a driven pulley andan idler pulley disposed on said frame structure in spaced relation forcarrying an endless sanding belt, and a pressure pad arrangedintermediate said tpaeef'i pulleys for applying the endless sanding beltto Work to be sanded, said pressure pad being mounted on a pivotedsupporting arm carried by said frame structure for pivoting movementabout a horizontal axis extending transversely between the working andreturn reaches of said endless belt, said supporting arm being furtherformed with a pivoted joint adjacent the point of pivoted support onsaid frame structure, the axis of said pivoted joint being disposed atright angles to said horizontal pivot axis and being positionedvertically when said supporting arm is disposed to position the pressurepad at its farthest downward extent, and said supporting arm beingdisposed with a pivoted extent in raised position substantially parallelwith the line of travel of said endless belt, wherebyadequate clearanceis provided for disposition and application of said pressure pad betweenthe working and return reaches of said endless belt by pulleys no largerthan are necessary for carrying said endless belt to the best advantage.

11. A sanding machine as dened in claim 9 and further characterized inthat a support piece is arranged on said frame structure directlybeneath said pressure pad together with guide strips for channeling workto be sanded to and from said support piece, said frame structure beingundercut beneath said pressure pad to receive said support piece, saidsupport piece and guide strips being formed to provide a free path forthe endless sanding belt when applied by said pressure pad to the fullcontour of the work to be sanded, and clamping means on said framestructure for positioning said support piece and guide strips thereon,said clamping means comprising arm members pivoted on said framestructure and clamping screws ntted at the extending ends of said armmembers for adjustment to clamp said support piece and guide stripsagainst said frame structure and thereby secure them in place.

References Cited in the le of this patent UNITED STATES PATENTS NumberName Date 445,382 Sawyer Jan. 27, 1891 645,717 Fletcher Mar. 20, 1900661,552 Rich et al. Nov. 13, 1900 844,368 Kitson Feb. 19, 1907 995,525Hanson Dec. 1, 1908 945,870 Sccvil Jan. 11, 1910 1,022,827 Cox Apr. 9,1912 1,136,146 Krohn et al Apr. 20, 1915 1,536,249 Walstrom May 5, 19251,749,898 Ward Mar. 11, 1930 1,821,624 Emmons Sept. 1, 1931 1,826,177Johnson Oct. 6, 1931 1,893,566 Solem et al. Jan. 10, 1933 1,978,149Stevenson Oct. 23, 1934 1,986,521 Oakley Jan. 1, 1935 1,990,668 PhilippiFeb. 12, 1935 1,995,382 Fenton Mar. 26, 1935 2,248,191 Pratt July 8,1941 2,272,273 Parker Feb. 10, 1942 2,313,254 Mead Mar. 9, 19432,407,499 Klossner Sept. 10, 1946 2,456,217 Rothrock Dec. 14, 1948FOREIGN PATENTS Number Country Date 15,465 Great Britain May 24, 1895

